l Your item on Oxford’s Low Emission Zone (Thursday’s Oxford Mail) is a nonsense.

The LEZ does not come into effect until January 1, 2014. It is therefore not surprising its effects are not apparent.

You also repeat the simplistic claim that St Aldate’s is the ninth most polluted street in England.

If every street in England had automatic air monitoring equipment by the side of the road – as St Aldate’s does – and St Aldate’s had come out ninth worst in a survey, this claim would be true. However, very few streets have automatic air quality monitoring equipment at the roadside and the claim is therefore a complete red herring.

Roger Pitman, Scientific Officer, Oxford City Council, and Martin Kraftl, Senior Transport Planner, Oxfordshire County Council